1. Field of the Invention
The present invention relates to a thin-film magnetic head for recording used in, for example, a floating magnetic head and, more particularly, to a thin-film magnetic head that features a toroidal coil configuration having lower resistance in connection between first coil segments and second coil segments and permits easy formation of the second coil segments, and a manufacturing method for the same.
2. Description of the Related Art
FIG. 12 shows a transferred partial front view of a thin-film magnetic head disclosed in Patent Document 1 (U.S. Pat. No. 6,275,354B1) described below.
The thin-film magnetic head shown in FIG. 12 is a “stitched pole type” thin-film magnetic head, in which a lower core layer 2, an insulating layer 3, a pole chip 4, and an upper core layer 5 are deposited on a substrate 1 in this order from the bottom, and a coil layer 6 is wound around the upper core layer 5.
In the pole chip 4, a lower magnetic pole layer 4a and an upper magnetic pole layer 4c are laminated with a gap layer 4b sandwiched therebetween.
The coil layer 6 is helically wrapped around the upper core layer 5, as shown in FIG. 12.
The coil layer 6 is constructed of a first coil segment 6a positioned above the lower core layer 2, a second coil segment 6b positioned above the upper core layer 5, and a side coil segment 6c, which is positioned beside the upper core layer 5 and formed continually from the first coil segment 6a and the second coil segment 6b. 
In FIG. 12, the insulating layer 3 is formed between the first coil segment 6a and the second coil segment 6b. The first coil segment 6a penetrates the insulating layer 3 in parallel to the upper surface of the substrate 1. Hence, the first coil segment 6a is electrically isolated from the upper core layer 5 through the intermediary of the insulating layer 3.
FIG. 13 is a transferred longitudinal sectional view of a magnetic head disclosed in Patent Document 2 (U.S. Pat. No. 6,163,435) described below.
Referring to FIG. 13, a lower core layer 12 has a protuberant portion 12a that projects in a direction of Z in the figure on a surface side opposing a recording medium. A magnetic pole 17 is formed on the opposing surface side of the protuberant portion 12a. 
As shown in FIG. 13, the lower core layer 12 has a back gap layer 13 formed near the back thereof in a height direction (Y-direction in the figure). A part of the coil layer 14 is accommodated between the protuberant portion 12a and the back gap layer 13. The coil layer 14 is encompassed by the insulating layer 15, and an upper surface 12b of the protuberant portion 12a, an upper surface 15a of the insulating layer 15, and an upper surface 13a of the back gap layer 13 are all flush, forming a planarized surface.
An insulating layer 16 is formed on the planarized surface formed by the upper surface 12b of the protuberant portion 12a, an upper surface 15a of the insulating layer 15, and an upper surface 13a of the back gap layer 13.
In the thin-film magnetic head disclosed in Patent Document 1 above, the side coil segment 6c substantially functions as a connection of the first coil segment 6a and the second coil segment 6b. However, no specific structure of the side coil segment 6c has been described.
Meanwhile, in the magnetic head disclosed in Patent Document 2, the insulating layer 16 is used merely to isolate the coil layer. Furthermore, the core structure around the magnetic gap of the thin-film magnetic head disclosed in Patent Document 2 above has been disadvantageous in achieving a narrower gap.